A soldier suspected of killing 16 Afghan villagers Sunday comes from Joint Base Lewis-McChord, one of the largest military installations in the U.S. — and one that has seen its share of controversies and violence in the past few years.The base, home to about 100,000 military and civilian personnel, has suffered a spate of suicides among soldiers back from war. The Army is investigating whether doctors at Lewis-McChord's Madigan Army Medical Center were urged to consider the cost of providing benefits when reviewing diagnoses of post-traumatic stress disorder. http://www.cbsnews.com/8301-201_162-57395145/shooting-suspect-from-most-troubled-u.s-base/?tag=stack